Refactor `ListGroup` open close handling

[nikku]

Proposed Changes

• Previously we would render the list group items delayed, with old (outdated) items to be rendered against new model data (ref)
• This caused bugs in downstream dependencies (https://github.com/camunda/camunda-modeler/issues/4382)

This PR puts list group, on stable foundations, without magic :tm: :registered:

Checklist

To ensure you provided everything we need to look at your PR:

• [x] Brief textual description of the changes present
• [ ] Visual demo attached
• [ ] Steps to try out present, i.e. using the @bpmn-io/sr tool
• [x] Related issue linked via Closes {LINK_TO_ISSUE} or Related to {LINK_TO_ISSUE}

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Related to https://github.com/camunda/camunda-modeler/issues/4382

[barmac]

There's one thing which I don't get. After I link it, the placeholder tests in the bpmn-js-element-templates start to fail:

Chrome Headless 121.0.6167.85 (Mac OS 10.15.7) provider/cloud-element-templates - CustomProperties placeholder should display placeholder (FEEL, String) FAILED
    AssertionError: expected '' to deeply equal 'Placeholder'
        at Context.eval (webpack-internal:///./test/spec/cloud-element-templates/properties/CustomProperties.spec.js:1662:36)
Chrome Headless 121.0.6167.85 (Mac OS 10.15.7) provider/cloud-element-templates - CustomProperties placeholder should display placeholder (FEEL, Text) FAILED
    AssertionError: expected '' to deeply equal 'Placeholder'
        at Context.eval (webpack-internal:///./test/spec/cloud-element-templates/properties/CustomProperties.spec.js:1673:36)

It looks unrelated though.

[barmac]

This was due to an outdated @bpmn-io/feel-editor on my machine. This is good now.